Trojan Boat Forum

Deck Re-Core Update

Last November I posted a thread introducing myself and told about my winter project of replacing the core in my front deck. This winter I removed the head and hull liner and stripped out everything above the V-bed in the forward state room. Well, the winter weather in Chicago was just too brutal to work on the actual core replacement, and I put the project on hold until spring. Well, spring is here and I’m finding the project slow going. Have you ever started a project and ask yourself “What have I done?”

I am replacing the core from underneath and started in the nose inside the anchor rope locker. The core in this area was the most heavily damaged. The core was totally saturated and had turned to mush. The primary source was at the anchor deck plate. Trojan used a hole saw to drill a hole through the deck, but didn’t glass the exposed balsa core. They probably caulked around the core, but it was gone before I bought the boat. When I cut through bottom layer of the fiberglass, water ran out. Once water gets into the core it is trapped, with no way of getting out. The balsa wood soaks it up like a sponge and spreads through the core. Once the water reached the cleats they got loose and more water was able to get in around the base of the cleats. When you look at the core through the bottom layer of glass, anywhere the core is wet, it looks dark. It looks dark in the area where the anchor chocks are located and around the hatches.

This picture shows the dark area around the front hatch. When I removed that area the core had collapsed and was no longed supporting the deck. There was a soft spot in the deck in that area. The core next to the soft spot was wet but still in tact. The core towards the bottom of the picture was dry and was in great shape, but I removed it anyways.



To maintain the shape of the deck, I put in 2 x ¾” white oak bows. I am putting in the bows every foot. I started with a piece of 5/4 x 2” white oak and ripped it in thirds. This gave me 3 pieces of oak 2” wide and ¼” thick. The ¼” thick pieces were able to bend and follow the bow of the deck. Once the 3 pieces are laminated with epoxy it forms the 2 x ¾” bow. Here is a picture of the core replacement and white oak bows.


I applied epoxy to all joints in the balsa core. I opened the joints, first width, then length, and brushed a generous coating. When the joint closed epoxy squeezed out of every joint.

To apply the epoxy to the bottom of the deck I mixed microballoons to the epoxy to thicken it. I then used a 3/16” notched trowel and coated the bottom of the deck. I also applied the thickened epoxy to the balsa core. When the balsa core was pressed into place, epoxy squeezed out from the sheet. I don't have any pictures of this step because my hands were covered with epoxy, and I didn’t want to get any on the camera.

Working over head is difficult, time consuming, and messy. Everything has to be propped while the epoxy dries. The boat has to be covered to protect it from drips, but the work is progressing.




When I got to the hatch I found that the plywood that is laminated into the deck needed to be replaced. It took a bit of doing to get the old pieces out. I set the new pieces in epoxy and ran the white oak bow in front and behind the hatch. I also ran a piece of oak between the bows on either side of the hatch.




I'm almost done with the core in the front state room. I will be applying the glass to the core soon. The thickness of the bottom layer of glass was about 1/8”. Trojan used their chop gun and sprayer a layer of glass on the core. They then covered it with a layer of woven roven. I’m thinking I will need to but two layers of 1.5 oz. mat, followed by a layer of woven roven. I used 7 sheets the balsa core to do the front state room and rope locker, plus 7 oak bows, each 2” wide and average 8’ long. Total area is about 70 square feet to glass. Over head glassing should be fun and a learning experance.

I'll continue to up date as the project progresses.

Wow that looks thorough but slow going. How many man hours have you put in so far?

Both my deck quotes were around 200 hrs which included the foredeck, raised deck foredeck, bow pulpit, both side decks, the aft deck under ladder and the large aft deck access cover.
My boat was a prime example of what happens when water penetration is left unchecked, it goes everywhere in the core, sounds like yours is much the same.
It took about three days for him to cut & remove top deck, remove core, lay new core and fibreglass over the core for the fore deck. As he was working in 1/4 sections the earlier recore photos don't make this clear as he actually was working on 2 sections at one time forward port deck and starboard cabin deck... then switch to other diagonals to maintain strength and shape while working. The deck was supported from underneath in the centre by a jack post. The last step was to do the gel coating (5 coats and 2 non skid) after everything was completed.

The repairs were well worth doing as the return to proper rigidity showed in the handling underway and made things quieter below decks.... she made noises before the fix.

I'm sure you will notice the difference when you have finished yours. Keep on truckin'

I think if I was to start over, I would work from the top. I have more hours in this project than I care to admit. My original thought was to save the non-skid texture of the deck. I can see now that the deck will require repairs in a number of places, which kind of defeats the idea of working from below. As that say, hind sight is 20/20.

Looks Like your doing a good job .

thanks for ur honesty....after seeing u doing the deck from the bottom i was thinking of doing that too...to save the top deck...im glad u said that u wouldnt do that in hidesight.....i guess ill be opening mine from the topside...anyone got a fiberglass can opener?

kevin babineau wrote:anyone got a fiberglass can opener?

You likely have the tools in your bag already.
Any that look like this?
Back in November before you joined there was some discussion here about doing the job, you can look for it by scrolling back.
Here is the link to my webpage with pictures of the work that was done on my F32.
http://www.flickr.com/photos/32233258@N ... 792002787/

I’m confident that what I have done is sound. When the core is taped from below it sounds solid. If there were any air trapped between the core and the deck the sound would be a dull thud rather then the solid ring I’m getting.

The balsa core is blocks of 3/4 “ balsa wood glued together with a fiberglass mesh backing to form a large continuous sheet 4’ wide. It is then scored by knife rollers 1” apart that cut half way through the wood. It is then cross cut and scored with another set of knife rollers 2” apart, with the end roller cutting completely through the sheet. The end result is a 2X4 foot sheet that has 1X2 inch blocks scored into the sheet. When the sheet is bent the wood breaks at the score cuts. As I stated earlier I broke the sheet at every score cut and brushed a generous amount of epoxy in each joint. By doing this, it gives a way for any air between the sheet of balsa core and the deck a way of getting out. Once the air is out and the epoxy dries it forms a rigid sheet that conforms to the contour and is bonded to deck.

When I glued the balsa core to the deck I put a piece of polyfilm between the core and the props. Once dry the props can be removed and the polyfilm removed. I then sand off any excess epoxy that oozed out from between the joints.

I found that it was easier to cut the balsa core with a razor knife then a saw. The razor knife makes clean precise cuts.

Working overhead is no fun. I go home very itchy with sore arms and a stiff neck.

Really really appreciate the pictures and words to go along with them. This is something I've been kicking around for a few years. In '99 I have a small area done by my local guy using your technique. It was the area right by the anchor chocks and rode hole leading to the locker. Same deal - core not glassed over and NO caulk under the mounts. I'm planning on removing the head liner over the v-berth area and going at it from the inside, but now the plan may change after reading about your experience!

randyp wrote:I'm planning on removing the head liner over the v-berth area and going at it from the inside, but now the plan may change after reading about your experience!

I hope it WILL change... working from below is by it's nature pushing uphill. Also it just has to take way more time to get the same thing done working against gravity. So why not gain a new gel finish on the topsides too.... it makes the boat look like a million dollars compared to dull old gel... easier to maintain too.
I redid the headliner in my F32 just because it looked old..... that was the most frustrating and time consuming job I've done on the boat. Stretching and stapling at the same time is no fun, and that was with extra material to pull on since it was a new install. I couldn't imagine replacing the old cut headliner without that extra material to pull on.
Of course my wife was saying I was too anal about trying to have it wrinkle free... but that was just me.
It was interesting trying to get it across the top of the bulkhead from V berth to dinette which is one piece headliner on the F32. Your layout may be different on your boat... I seem to remember when I was looking at 26's, before I concluded they were too small for spending time out on the hook, that they were more open than the F32 so you may not have that issue.

ready123 wrote:

randyp wrote:I'm planning on removing the head liner over the v-berth area and going at it from the inside, but now the plan may change after reading about your experience!

I hope it WILL change... working from below is by it's nature pushing uphill. Also it just has to take way more time to get the same thing done working against gravity. So why not gain a new gel finish on the topsides too.... it makes the boat look like a million dollars compared to dull old gel... easier to maintain too.
I redid the headliner in my F32 just because it looked old..... that was the most frustrating and time consuming job I've done on the boat. Stretching and stapling at the same time is no fun, and that was with extra material to pull on since it was a new install. I couldn't imagine replacing the old cut headliner without that extra material to pull on.
Of course my wife was saying I was too anal about trying to have it wrinkle free... but that was just me.
It was interesting trying to get it across the top of the bulkhead from V berth to dinette which is one piece headliner on the F32. Your layout may be different on your boat... I seem to remember when I was looking at 26's, before I concluded they were too small for spending time out on the hook, that they were more open than the F32 so you may not have that issue.

The headliner in the F36 is different then the F32. The liner in the dinette area is seperate from the V-birth and hall. There are 4 pieces of liner that make up the v-berth and hall. When the time comes, I will be installing new headliner. And you're not anal, wrinkles in the headliner is not acceptable.

gjrylands wrote: And you're not anal, wrinkles in the headliner is not acceptable.

Thanks, I'll show that to her.... yea right
Secrets of a happy marriage.... "yes dear thats right and do you want me to do that now?"

Nice work so far

Another Update

Persistence prevailed!

The core is done in the forward state room and I have a layer of glass on the ceiling/underside of the deck. I will still need to put at least another layer on, but that can be done in the harbor. I’ve got multiple layer of glass in the anchor rope locker so I can now reinstall my deck cleats. This is a major milestone to getting ready to launch. With the layer of glass on multiple layer the underside of the deck the deck is now rigid enough to walk on. I am going to glass in some temporary patches tomorrow on the spots in my deck where there are cracks. This will keep water out of the new core until I get around to making permanent repairs. Once that’s done, the shrink wrap can come off.

I’ve scheduled a launch date for next Wednesday 6/3/09. I’ll have a week to wash and wax the hull, paint the bottom, and de-winterize the boat. If all goes well and the creek don’t rise, I’ll be in the harbor by next weekend.

Let me tell you, over head glassing has been a learning experience. What a mess! I’ve been up to my arm pits in epoxy. I won’t be needing any hair spray, the epoxy has given me all the hold I need and then some. Ever try washing your hair in acetone? You won’t like it.

Glassing in the rope locker was terrible. Trying to work through the door opening was difficult to say the least. That’s where the hair really got coated. I’m glad that part is history. I still have the edges to do with fiberglass tape, but that should be a piece of cake compared to the woven roving.

Would like to see your pictures before you put the headliner back. I'm getting all worked up to tackle the front deck, and now I'm convinced to go at it from the top. I know someone here that redid the forward deck of my boat's big brother, an F-32. He did it from the top, using a circular saw set to slice through the non-skid and most of the balsa core in sections without cutting into the bottom fiberglass layer. His approach was to replace the core with foamcore (from Jamestown Distributors) and then replace the top nonskid with fiberglass mat, gel coat and non-skid additve. I'm thinking that there has to be non-skid surface sold in sheets. Like I said, getting all worked up to tackle this once the boat comes out of the water this fall. It's stored indoors. Of course, I always reserve the right to dip into the kids' inheritance and just pay a real expert to do the job for me (older and wiser now that I'm just about eligible for Medicare and that leftover Gov't cheese stored in some warehouse......)